Articles by RICHARD C VOGT
The objective of this study was to identify and describe the nesting habitat of Podocnemis sextub... more The objective of this study was to identify and describe the nesting habitat of Podocnemis sextuberculata at Erepecu Lake, Trombetas River Biological Reserve, (REBIO-Trombetas; Pará-Brazil). Initially, the main features of the beaches that potentially determine the habitat selection by cupiso for nesting were described. The nests observed on the beaches were recorded, marked and fenced as protection from natural predators. Information regarding date and location was analyzed with simple linear regression for each nest in order to determine relationships between beach features and number of nests. The results showed a positive co-relationship between number of nests and area. Nest site selection by P. sextuberculata in the beaches of the Erepecu Lake could depend on trade-off scenarios among natural threats and a suitable nesting habitat. We also suggest that, due to the high annual hydrologic oscillations on the beaches, it is possible that the driving factor for habitat selection would be the risks that the species is exposed to at the time of the search for a nesting site, rather than seeking a particular habitat type.
Papers by RICHARD C VOGT
The purpose of this application, under Article 23.9.3 of the Code, is to conserve the specific na... more The purpose of this application, under Article 23.9.3 of the Code, is to conserve the specific name Podocnemis unifilis Troschel, 1848, for a widely distributed species of Amazonian turtle (family PODOCNEMIDIDAE) of both economic and conservation importance, by giving it precedence over its infrequently used senior synonym Podocnemis cayennensis . This species, the Yellow-spotted River Turtle, has long been referred to as P. unifilis by the IUCN Red List and CITES, as well as in at least 200 scientific publications over more than a century, whereas the name P. cayennensis has only been applied to this species in very few recent publications. Prior to 1974, the name cayennensis had usually been used incorrectly for another species, the Red-headed River Turtle, Podocnemis erythrocephala (Spix, 1824), as noted and corrected by Mittermeier & Wilson (1974) and . The conservation of the binomen P. unifilis will stabilize the use of a name that has been in general use for this species in the vast majority of the scientific publications, government documents, endangered species lists, and the general literature for over 100 years. Giving precedence to the older name (cayennensis) would be counter to usage, and would create much confusion in the literature.
Biota Neotropica, 2013
The lower Purus River Basin, Central Amazonia -Brazil, represents an area of prominent interest f... more The lower Purus River Basin, Central Amazonia -Brazil, represents an area of prominent interest for conservation of amphibians and reptiles. However, there is little available information about these groups for flooded and nonflooded forests, the major landscapes in this region. We sampled a representative area over two periods : 2004-2005 and 2009-2010. We used efficient and complementary techniques for sampling the herpetofauna in rainforests: time constrained audio-visual search (TAVS), pitfall traps with drift fence (PFDF) and doubleended funnel traps with drift fence (FTDF). We recorded a total of 160 species, including 75 amphibians (73 frogs and two caecilians) and 85 reptiles (34 lizards and 51 snakes). The occurrence of the anuran Dendropsophus allenorum represents the first record for Brazil. Comparing the efficiency of the sampling methods, the TAVS was the best method in sampling efficiency for the majority of the herpetofauna species; followed by the PFDF, efficient in sampling terrestrial frogs and litter lizards in the nonflooded forests. We did not use the PFDF in the flooded forests because the soil was water saturated. Despite its low efficiency in sampling terrestrial frogs and litter lizards, the FTDF, was efficient in snake capture and easily adaptable to the saturated soil in flooded forests. The greatest richness of species and groups was found in the nonflooded forests. Families of fossorial and litter species were mostly absent from the flooded forests. However, in the flooded forests we found a large number of arboreal frogs (Hylidae) and of larger heliothermic lizards (Teiidae). When we evaluated each sample period separately, we found a similar richness of the herpetofauna between the different types of forest landscapes, with a bias towards higher diversity in the nonflooded forests. In spite of similar species numbers, the nonflooded and flooded forests had different species assemblages. The total amphibian and Squamata reptilian diversity between the nonflooded and flooded forests (beta-β diversity), sites with more widespread landscapes, possibly represents the major contribution to the regional herpetofauna diversity in the lower Purus River Basin (Gama-γ diversity).
Archives of Environmental Contamination and Toxicology, 2010
Mercury levels in the Amazon River are generally high, but there are no published studies on Hg l... more Mercury levels in the Amazon River are generally high, but there are no published studies on Hg levels in turtles from the region. In this study, levels of Hg were examined in the muscle of six species of turtles in the Rio Negro in the Amazon basin of Brazil, including Podocnemis unifilis, Podocnemis expansa, Podocnemis erythrocephala, Podocnemis sextuberculata, Peltocephalus dumerilianus, and Chelus fimbriatus. It is important to analyze Hg levels in chelonians in this region because of the potential health risk to humans and other receptors that eat them, as well as their potential use as bioindicators. The effect of sex, weight, and carapace length on Hg
Herpetologica, 1999
We describe a new species of small, terrestrial, montane pitviper (Cerrophidion)from extreme sout... more We describe a new species of small, terrestrial, montane pitviper (Cerrophidion)from extreme southern Sierra Madre Oriental in Veracruz, MCxico. It differs from other members of the genus in scalation, coloration, color pattern, and hernipenial ornamentation. We also report the effect of the first known case of snakebite on humans for this species as well as aspects of its ecology.
Objetivo. Analizar los comportamientos de alimentación bajo diferentes condiciones de temperatura... more Objetivo. Analizar los comportamientos de alimentación bajo diferentes condiciones de temperatura en un grupo de neonatos de Peltocephalus dumerilianus (Testudines Podocnemididae). Materiales y Métodos. Los individuos experimentales fueron obtenidos mediante incubación en el laboratorio, se dividieron en 5 grupos al azar. Durante 2 meses con tres repeticiones a la semana se hicieron pruebas de temperatura utilizando dentro de las bandejas calentadores eléctricos, con registro continuo de temperatura mediante termómetro digital -10 a + 60ºC (± 0.1ºC), procurando mantener un ritmo constante de incremento equivalente a 0,25ºC cada 10 minutos, hasta llegar a la temperatura seleccionada, que fue mantenida por 60 minutos en cada ensayo. Las temperaturas seleccionadas para cada ensayo, fueron: 26ºC, 30ºC, 34ºC, 38ºC y ambiente que fue de 26,8ºC en promedio. Fueron evaluados los siguientes parámetros: duración en minutos de la ingesta, tiempo de inicio de comportamientos agonísticos, presencia de dos tipos de despliegues característicos: morder y disputa por alimento. Resultados. En general todos los parámetros fueron significativos, a mayor temperatura el tiempo de ingestión fue mayor, a menor temperatura el volumen de consumo fue menor, a menor temperatura el inicio de los despliegues agonísticos fue mayor y se mantuvo una relación inversamente proporcional. Conclusiones. Los resultados mostraron que existe relación directamente proporcional entre la temperatura ambiental y los procesos de alimentación, además que se relacionaron con aspectos básicos del comportamiento lo cual se manifestó en los despliegues agonísticos observados.
Acta Ethologica, 2009
The courtship behavior of Podocnemis erythrocephala (Red-headed Amazon River Turtle) in captivity... more The courtship behavior of Podocnemis erythrocephala (Red-headed Amazon River Turtle) in captivity was studied to examine female receptivity and male response to female rejection. We observed 20 females and 39 males in 150 sessions (3-6 h/day for a total of 450 h). In 36% of the trials, there was no interaction between males and females, and 20% of the trials resulted in copulations. All males introduced into tanks approached females, and eventually there was aggression among the males. In 48% of the experiments, females also searched for or approached males. When males initially approached females, they either accepted the male's advances (14%), rejected the male passively (38%), or rejected the male aggressively (48%). In 86% of the cases where males were rejected, 4% attempted to approach females again, and in 51% they were ultimately successful.
Chemosphere, 2015
Keratin is a better predictor of exposure to Hg than muscle and bone. Keratin layer only should b... more Keratin is a better predictor of exposure to Hg than muscle and bone. Keratin layer only should be used to study Hg in epidermis of reptiles. Disagreement between previous studies is attributed to inconsistency in methods. Carapace growth rings are useful for estimating Hg bioaccumulation over time.
Journal of Toxicology …, 2009
Using blood as a method of assessing metal levels in turtles may be useful for populations that a... more Using blood as a method of assessing metal levels in turtles may be useful for populations that are threatened or endangered or are decreasing. In this study the levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in blood of four species of turtles from the tributaries of the Rio Negro in the Amazon of Brazil were examined. The turtles included the six-tubercled Amazon (river) turtle (Podocnemis sextuberculata), red-headed Amazon (river) turtle (Podocnemis erythrocephala), big-headed Amazon (river) turtle (Peltocephalus dumerilianus), and matamata turtle (Chelus fimbriatus). Blood samples were taken from the vein in the left hind leg of each turtle. There were significant interspecific differences in the sizes of the turtles from the Rio Negro, and in concentrations of Pb, Hg, and Se; the smallest species (red-headed turtles) had the highest levels of Pb in their blood, while Se levels were highest in big-headed turtles and lowest in red-headed turtles. Hg in blood was highest in matamata, intermediate in big-headed, and lowest in the other two turtles. Even though females were significantly larger than males, there were no significant differences in metal levels as a function of gender, and the only relationship of metals to size was for Cd. Variations in metal levels among species suggest that blood may be a useful bioindicator. Metal levels were not high enough to pose a health risk to the turtles or to consumers, such as humans.
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Articles by RICHARD C VOGT
Papers by RICHARD C VOGT